Many security sensors mount to a wall near a door or window to sense whether the door or window is opened, and to send a wirelessly transmitted signal to a central controller. Such sensors are battery operated, and may contain a circuit board and an antenna, along with a magnetic switch. When such sensors are mounted near metal, such as is used in many forms of commercial construction, performance and range of the wireless transmission can be impeded by the metal near the sensor. To alleviate degraded performance of the wireless transmissions, power levels have been increased, and antennas lengthened. In some cases, a rabbit tail antenna has been used, extending outside a sensor enclosure, which is not aesthetically pleasing and is also subject to efforts to tamper with the sensors.